Fire alarm



S. G. MILLER Feb. 4, 1958 FIRE ALARM Filed Sept; 16, 1955 INVENTOR.

BY 44d Sidney 6. Miller Fig.5

United States PatetitO FIRE ALARM Sidney G. Miller, Moosup, Conm, assignor of fifty percent to Frank R. Odlum, Hartford, Conn.

Application September 16, 1955, Serial No. 534,637

7 Claims. (Cl. 340-227) This invention relates to a 'fire'alarm, and more particularly to a device which'is'capab'leof being associated with an electric outlet box or the-like soas to provide a the provision of a portable fire alarm capable of being transported from one location to another and having prongs insertable into a conventional electric outlet receptacle. Further, the invention provides means for enabling the fire alarm to be set to operate at a selected predetermined temperature.

The construction of this invention features afire alarm including novel indicating-and setting meansand further including a novel arrangement of parts whereby'electric power is supplied'not only to a: coil for actuating a vibrator but to a contact brush actuated bya bimetallic coil and to' an adjustable contact mounted for rotary movement.

Still further objects and features of this invention re-' side in the provision of a firealarm' that is simple in construction, highly efiicient in operation,-'light in weight, and inexpensive to manufacture; thereby permitting wide distribution and utilization;

These, together with the various ancillary objects and features of the invention which will become apparent as the following, description proceeds, are attained by this fire alarm, a preferred embodiment of vwhich has been illustrated in the accompanying drawings, by way of example only, wherein Figure 1 is a perspective view of the fire alarm comprising the present invention from the front portion thereof;

Figure 2 is a rear perspective view of the fire alarm;

Figure 3 is an enlarged vertical sectional view as taken along the plane of line 3-3 in Figure 1 and illustrating in particular the construction of the adjustable contact;

Figure 4 is a vertical sectional view as taken along the plane of line 4-4 in Figure 3 and illustrating the manner in which the coil is positioned Within the housing;

Figure 5 is a vertical sectional view as taken along the plane of line 55 in Figure 3; and

Figure 6 is a schematic diagram of the electrical components of this invention.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral 10 is used to generally designate the fire alarm comprising the present invention. This fire alarm includes a housing which can be either made of metallic or plastic material and which includes a base plate 12 having a peripheral flange 14 within which the housing cover 16 is adapted to sea. The housing cover 16 has an extension 18 which may be covered with a suitable transparent face plate 20 in order that the indicia 22 on the dial plate 24 can be readily observed.

An insulative plate 26 is positioned in overlying rela- 4 aazassr Patented F eh. 4, 195.8

.2 tionship relative to the base plate 12 and carries'a pairol' prongs 28 and 30. Studs havingscrewheadsandindi cated by reference numerals 32 and 34-extend. through the plate 32 and through the base plate 12 and not only only hold theprongs 28 and30 in position" but also support and position a coil 36 as well as the lower end of the dial plate 24, as indicated at 38. The dial'plate 24is, of course, made of a suitable number of 'laminations of metallic material or may be integrally'formed. The studs 32 and 34 have threaded end' portions which extend through the cover plate '16 and cap nuts 40 and 42 are threaded-1y engaged on the ends of the studs32 and'34 to hold the cover plate 16 in position.

By means of conductor 48, the prong 28 is electrically operatively connected to the coil 36 and conductor 50 connects the coil 36 to a bimetallic temperature responsive member 52 which can be best seen in Figures 3 and S. The temperature responsive member 52 carries an indicator 54 which cooperates withthedial 22 to indicate thetemperature of the area surrounding the fire alarm 10 and carries a carbon contact brush 56 which is movable into engagement with an adjustable contact rod 58 carried by an-adjustable insulative contact member '60. The carbon brush'56 may obviously be made out of any other suitable electricallyconductive material, if so desired. The contactrod-SS -extends'angularly outwardly from the contact memberx60 and is an extension of the member 62 fixingtheinsulative contact member'60 to a disk 64. Another rod 66 is also utilized to mount the insulative contact member 60on'the disk 64;; Anoperating shaft 68 extends through the base plate 12, the insulation 7t) separating the electrically conductive disk 64 from the base plate 12, and through suitable Washers 72 and is engaged in the insulative contact'member64 and rotatable therewith so that upon operation of the operating shaft 68, the member 60 will rotate; as will the contact rod 58 and the disk 64. The disk, 64 is engaged'by a resilient contact brush 76 whichis *electrio'allYoperatively connected to the prong 30.

Carried by the insulative contact member 62 is, a finger 78 which extends through a slot 80 in thefldial'plate 24 and which holds the upper portions ofthe' dialiplate'24 in position, thus cooperating with the studs 32 an'd 34 to maintain the dial plate inpositionr A vibratingmern her 82 is held by'means of a screw-fastener' 84lor the like in position so as to be actuatable by the coil 36 when the coil 36 is excited.

In operation, the operating shaft 68 is rotated so that the indicator 78 will indicate the temperature at which the surrounding area must be so as to actuate the temperature responsive element 52 to that temperature which will thus cause the contact brush 56 to engage the contact rod 58 to complete an operative electrical circuit from the source of electric power at the prongs 28 and 30 to the coil 36 thus actuating the vibrating element 82 to sound a buzzing noise or the like.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. A fire alarm comprising a housing having a base plate, a pair of contact prongs extending from said base plate for connection to an electric outlet to support and electrically energize said fire alarm, a coil electrically connected to one of said prongs, a vibrator actuated by said coil, spaced support studs carrying said coil, a dial plate carried by said studs, a temperature responsive member carried by said dial plate and having a contact brush associated therewith electrically connected to said coil, and an adjustable contact carried by said base plate, said adjustable contact being electrically connected to the other of said pair of prongs and being engageable by said contact brush.

2. A fire alarm comprising a housing having a base plate, a pair of contact prongs extending from said base plate for connection to an electric outlet to support and electrically energize said fire alarm, a coil electrically connected to one of said prongs, a vibrator actuated by said coil, spaced support studs carrying said coil, a dial plate carried by said studs, a temperature responsive member carried by said dial plate and having a contact brush associated therewith electrically connected to said coil, and an adjustable contact carried by said base plate, said adjustable contact being electrically connected to the other of said pair of prongs and being engageable by said contact brush, said dial plate having an arcuate slot therethrough, said adjustable contact having a finger extending through said slot.

3. A fire alarm comprising a housing having a base plate, a pair of contact prongs extending from said base plate for connection to an electric outlet to support and electrically energize said fire alarm, a coil electrically connected to one of said prongs, a Vibrator actuated by said coil, spaced support studs carrying said coil, a dial plate carried by said studs, a temperature responsive member carried by said dial plate and having a contact brush associated therewith electricallyconnected to said coil, and an adjustable contact carried by said base plate, said adjustable contact being electrically connected to the other of said pair of prongs and being engageable by said contact brush, said adjustable contact having a coutact ring mounted on and insulated from said base plate, and a strip brush connected to said other of said pair of prongs resiliently engaging said contact ring.

, 4. A fire alarm comprising a housing having a base plate, a pair of contact prongs extending from said base plate for connection to an electric outlet to support and electrically energize said fire alarm, a coil electrically connected to one of said prongs, a vibrator actuated by said coil, spaced support studs carrying said coil, a dial plate carried by said studs, a temperature responsive member carried by said dial plate and having a contact brush associated therewith electrically connected to said coil, and an adjustable contact carried by said base plate, said adjustable contact being electrically connected to the other of said pair of prongs and being engageable by said contact brush, said temperature responsive member including a coil of bimetallic material.

5. A fire alarm comprising a housing having a base plate, a pair of contact prongs extending from said base plate for connection to an electric outlet to support and electrically energize said fire alarm, a coil electrically connected to one of said prongs, a vibrator actuated by saidcoil, spaced support studs carrying said coil, a dial plate carried by said studs, a temperature responsive member carried by said dial plate and having a contact brush associated therewith electrically connected to said coil, and an adjustable contact carried by said base plate, said adjustable contact being electrically connected to the other of said pair of prongs and being engageable by said contact brush, said adjustable contact having a contact ring mounted on and insulated from said base plate, and a strip brush connected to said other of said pair of prongs resiliently engaging said contact ring, said dial plate having an arcuate slot therethrough, said adjustable contact having a finger extending through said slot, said temperature responsive member including a coil of bimetallic material.

6. A visual indication switch for a fire alarm comprising a coil, spaced support studs carrying said coil, a dial plate carried by said studs, a temperature responsive member carried by said dial plate and having a contact brush associated therewith electricallyconnected to said coil, and an adjustable contact, said adjustable contact being engageable by said contact brush, said adjustable contact having a contact ring, and a strip brush resiliently engag ing said contact ring, said dial plate having an arcuate slot .therethrough, said adjustable contact having a finger extending through said slot.

7. A visual indication switch for a fire alarm comprising a dial plate, a temperature responsive member carried by said dial plate and having a contact brush associated therewith, an adjustable contact, said adjustable contact being engageable by said contact brush, said adjustable contact having a contact ring, and a strip brush resiliently engaging said contact ring, said dial plate having an arcuate slot therethrough, said adjustable contact having a finger extending through said slot.

2,456,038 Young Dec. 14, 1948 

